This invention relates, in general, to semiconductor processing, and more particularly, to removal of contamination during semiconductor processing.
At the present time, contamination reduction of fluids used for processing semiconductor wafers is focused on reduction and/or removal of particles from the fluids. Typically, reduction and removal of contamination or particles from the fluids are achieved by a filtration process that passes the fluid across a filtering medium. Generally, the filtering medium is made of an inert substance with a multitude of small pores that allow the fluid to pass from one side of the filter to the other while capturing the particles in the filtering medium as the fluid passes through. While reduction and removal of particles from fluids used in processing semiconductor wafers are very important, reduction and removal of particles do not remove metallic contamination in the fluid.
As semiconductor devices continue to shrink while at the same time increase in complexity, metallic contamination problems become more apparent and affect the semiconductor devices that are made on the semiconductor wafers. The metallic contamination of the semiconductor wafers during processing results in several problems with the semiconductor devices, such as degradation of time-dependent dielectric breakdown (TDDB), increased current junction leakage, and reduced lifetime of the semiconductor device. Ultimately, these problems result in reliability failures of the semiconductor device.
It can be readily seen that conventional particle contamination control of fluids used in processing semiconductor wafers is not sufficient to eliminate or to reduce metallic contamination. Additionally, because of the decreasing size of semiconductor devices and the increasing complexity of the semiconductor devices, problems with metallic contamination will increase. Therefore, an apparatus and method for removing metallic contamination from fluids used in semiconductor processing, as well as filtering fluids used in semiconductor processing would be highly desirable.